In general, X-rays are electromagnetic waves having a wavelength of about 0.01 Å to about 100 Å. Since the X-rays have a property that allows them to penetrate objects, they may be widely used in medical equipment, which photograph the insides of organisms, or nondestructive testing equipment for general industry.
An X-ray apparatus may acquire an X-ray image of an object by transmitting X-rays, which are emitted from an X-ray source, through the object and detecting the intensity differences between the transmitted X-rays by an X-ray detector. The X-ray apparatus may detect an internal structure of the object from the X-ray image to diagnose the object. The X-ray apparatus may easily detect the internal structure of the object on the basis of the principle that the X-ray transmittance varies according to the densities of the object and the atomic numbers of atoms constituting the object. As the X-ray wavelength decreases, the X-ray transmittance and the screen brightness thereof increase.
Mammography uses an X-ray apparatus to capture an X-ray image of a breast. Mammography is one of the best non-invasive testing methods for detecting breast cancer. In the related art, since a user has difficulty in detecting an error, which may be caused by a filter error, a collimation error, or an error due to an implant inserted into a breast, from a pre-shot image, the user has to perform rephotographing after acquisition of a main-shot image.